In 2003, Gulf began working with Reliance Industries Limited (RIL), assisting RIL with the preliminary engineering for its proposed East - West Gas Pipeline, an ambitious project to construct a multi-billion dollar 48-inch diameter natural gas pipeline traversing the entire sub-continent of India, stretching almost 1, 400 kilometers from the east coast to the west coast. The project was RIL's first venture into the pipeline business, developed to exploit the reserves of a large offshore gas field that RIL discovered off the northeast coast of India. The East West Pipeline supplies RIL's vast petrochemical complex at Gujarat in northwest India and delivers gas to numerous customers via branch line connections along its length. The pipeline system features multiple compressor stations, numerous metering facilities at branch take-offs and an advanced control and communications network. The project is the first and largest cross-country pipeline in India and the backbone of India's burgeoning natural gas grid, but for a time it looked like India's biggest pipeline project might never be built.

The founder of Reliance and patriarch of the family, which owned the company, passed away in 2004, his demise instigating a dispute between his two sons over control of the vast Reliance business empire. In late 2005, the brothers resolved their disagreement and RIL, with whom Gulf had continued to work at an unhurried pace during the dispute, accelerated the project. Gulf began detailed engineering and procurement activities on the pipeline, working closely with RIL to define and document the end-to-end execution requirements for the project.

Constructed from 2006 through 2008, the project presented RIL and Gulf with a profusion of economic, technical and political challenges. During this time, the world economy boomed and India's economy overheated, constraining all resources, financial, materials, personnel and equipment, pressing performance challenges upon the project participants, some of whom succumbed to the difficult and demanding circumstances. Gulf persevered and played an important role, performing full EPCM services, but more importantly in assisting, advising and guiding RIL's approach to a successful completion of the project.